2012 Mercedes-Benz ML63 AMG - Super Truck

Driving the world’s most powerful SUV.

One Mississippi, two Mississippi, three Mississippi, four Mississippi, five Mississ... and that’s how quickly a 5,159-pound SUV can zip from standstill to 60 mph. About 4.7 seconds, providing it’s the 2012 Mercedes-Benz ML63 AMG (or one of its rivals).

The hardware responsible for this particular affront to physics is a 5.5-liter V8 with two turbochargers helping to develop 518 horsepower and 516 lb-ft of torque. And like every other AMG engine, this one is hand-assembled in Affalterbach, Germany. The seven-speed transmission is built in Stuttgart. Both items are then shipped over to Alabama, from where all M-Class vehicles originate.

This model (the only AMG vehicle made in the United States) is based on the new generation of M-Class, whose regular versions debuted in late 2011. It bears the usual AMG additions such as beefier brakes, aerodynamic body kit, adaptive air suspension and plenty of gadgets. In recent times, Benz’s performance division has also taken to fitting flat-bottomed steering wheels to its cars, which feel pleasantly chunky; a sensation enhanced by Alcantara covering at the quarter-to-three positions and leather elsewhere.

Mercedes-Benz claims it invented the performance SUV niche, now joined by vehicles like the BMW X5 M and the Porsche Cayenne Turbo. None of them are cheap but they cover so many bases so well. The ML63 AMG, with the optional Performance Package that boosts horsepower to 550 and torque to 560 lb-ft, has the added distinction of being the most powerful production SUV in the world.

Its permanent all-wheel-drive system sends 40 percent of engine output to the front axle, 60 percent to the rear. The result is a slightly more sporty, rear-driven feel to the chassis (the regular M-Class has a 50:50 split). But there’s not even the suggestion of a wayward tail, especially when there are non-defeatable traction and stability controls. The ML63 goes into, through and out of corners with absolute composure; this chassis was tuned on the Nürburgring. And the spacing of the gear ratios seems perfect, the transmission never feels like it’s in too high or too low a gear.

Meanwhile, an air of absolute luxury pervades the cabin. The dash is covered in leather; there are options of wood, piano black or brushed aluminum trim pieces; a Harmon Kardon audio system is standard, offering satellite radio, Bluetooth and iPod connection. Navigation with real-time traffic and weather is also standard, along with Attention Assist and 10-way power-adjustable front seats.

Reviews of machines with more than 500 hp don’t tend to mention storage space all that much, but having the ability to fill 71 cubic feet with luggage or groceries or antique wardrobes, close the power liftgate on them and then travel at speeds of up to 174 mph is a particular kind of crazy wonderful.

It’s the kind that comes at a price, however. Including destination and delivery charges, the MSRP starts at $95,865. That buys a lot of standard equipment, including active roll bars. These have the ability to disconnect themselves should the ML63 venture off the road and require some axle articulation. And then they snap back into place once the tarmac is under the tires.

All ML models also have Active Curve Control, which is an anti-rollover system. It orchestrates the traction and stability controls, and brakes an outside rear wheel if it senses a catastrophe in the offing.

There are still some options that might be worth having though, even if they do hike up the price. Night vision, for example. Perhaps the rear-seat DVD system. And the Bang & Olufsen surround-sound audio is just fantastic.

The Performance Package costs another $6,050. By raising turbo pressure from 14.5 to 18.8 psi, it shortens the zero-to-60 mph sprint by a tenth of a second. These numbers may seem rather meaningless in cold black and white, but the extra torque can be felt and appreciated. The only exterior sign that someone has opted for this pack is the red paint on the brake calipers.

Here’s the one major gripe: the steering feels artificial. The culprit, of course, is the electro-mechanical assistance. As soon as the steering wheel comes a few degrees from straight ahead, the system kicks in too aggressively and there’s no real feel to what the front tires are doing. With the optional Active Lane Keeping system, it’s the same story: too much, too soon. Because this can be a family car, the reasoning behind having electric assistance instead of hydraulic (which wouldn’t be compatible with Active Lane Keeping) is understandable. It looks like we’ll just have to wait for such systems to evolve and improve. In the meantime, there’s still the rest of the car to enjoy.